A) the ratio of their masses is always the same. B) their masses are always equal. C) their volumes are always equal. D) each element contributes an equal number of atoms.
A) Negative and positive charges are spread evenly throughout an atom. B) There is a dense, positively charged mass in the center of an atom. C) Gold is not as dense as previously thought. D) Alpha particles have a positive charge.
A) concentrated in the center of an atom. B) concentrated at multiple sites in an atom. C) located in the space outside the nucleus. D) spread evenly throughout an atom.
A) electron B) neutron C) proton
A) Unlike protons or neutrons, electrons have no mass. B) An electron has far less mass then either a proton or a neutron. C) Neutrons have no charge and no mass. D) Protons, neutrons, and electrons all have about the same mass.
A) the charge on the electrons B) the number of neutrons C) the mass of the neutron D) the number of protons
A) mass number B) charge C) atomic number D) isotope
A) atomic number from mass number B) isotope number from atomic number C) atomic number from electron number D) mass number from atomic number
A) like beach balls on water waves. B) like popcorn in a popper. C) like planets orbiting the sun. D) like balls rolling down a hill.
A) the mass of the electrons in the atom B) the precise location of electrons in an atom C) the most likely locations of electrons in an atom D) the number of electrons in an atom
A) they are located in the left-most column of the periodic table B) they are usually gases C) they form negative ions D) the are extremely nonreactive
A) electric charge of a substance B) volume of a substance C) mass of a substance D) amount of a substance
A) isotope number B) mass number C) atomic number D) atomic mass unit
A) its atomic mass B) how tightly atoms are packed in the element C) the number of valence electrons in atoms of the element D) the ratio of protons to neutrons in atoms of the element
A) They are isotopes of oxygen B) They have the same mass number C) their masses are identical D) they do not have the same number of protons
A) row to row B) group to group C) element to element D) column to column
A) helium, carbon, gold B) phosphorus, nitrogen, oxygen C) sodium, chromium, copper D) iodine, iron, nickel
A) the discovery of subatomic particles. B) the discovery of the nucleus. C) the discovery of elements with predicted properties. D) the immediate acceptance by other scientists.
A) three B) four C) two D) none
A) increases then decreases B) increases C) stays the same D) decreases
A) proton B) neutron C) carbon-12 atom D) chlorine-35 atom
A) -2 B) 0 C) -1 D) +1
A) 1/1840 B) 0 C) 1 D) 1/18
A) period B) number of neutrons C) chemical properties D) mass
A) changing from one period to another B) changing from lithium into fluorine C) losing or gaining electrons D) losing or gaining protons
A) one-half the mass of a hydrogen atom B) one-fifteenth the mass of a nitrogen-15 atom C) one-fourth the mass of a lithium atom D) one-twelfth the mass of a carbon-12 atom
A) they can form compounds with bright colors B) They exist as single elements rather than molecules C) they are highly reactive D) they are rare in nature
A) have large atomic masses but small atomic numbers B) can conduct electric current only under certain conditions C) are extremely hard D) do not form compounds
A) on the bottom B) on the left C) on the right D) in the middle
A) one gram of a pure substance B) one kilogram of a pure substance. C) one mole of a pure substance D) one liter of a pure substance
A) 80 B) 35 C) 79 D) 172
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